The 50 states have long been, as Justice Louis Brandeis famously said, “laboratories of democracy,” or testing grounds for innovative policies that can then spread across the country.

In the case of clean energy, the unique characteristics of each state — geography, economy, natural resources and workforce — have made the states ideal settings for building markets for renewable energy technologies. Because the states embraced a central role in policy development and implementation, clean energy generation has grown more than seven times faster than experts envisioned just a few years ago. But after years of success, how can states continue to innovate and remain on the cutting edge?

First, states can identify and focus on emerging issues that have not received adequate attention. California did that when it instituted an energy storage mandate, requiring investor-owned utilities to make significant investments in batteries and other storage capacity. Similarly, states are increasingly focusing on making solar technology available to low-income households and communities. This ensures that solar’s benefits are distributed widely through society.

California recognized this important issue, when, as part of the Go Solar California Initiative, it enabled households with the lowest incomes to apply to receive fully subsidized 1-kilowatt solar installations, while other low-income households were eligible for partially subsidized systems. Washington, D.C., adopted a similar program, Solar Advantage Plus, to provide low-income households with zero-cost solar electricity, saving them about $500
annually. These trailblazing programs helped set the stage for President Barack Obama’s recently announced low-income solar initiative, which includes tripling the amount of solar on federally subsidized housing by 2020.

States should also emphasize program evaluation. Many clean energy initiatives have been in place long enough to provide sufficient data to measure impacts and cost effectiveness. These evaluations should explicitly focus on ways to improve current state programs. California, for example, has collected thousands of pages of data related to the California Solar Initiative to help the California Energy Commission and California Public Utilities Commission assess the effectiveness of past and future policies. Other states should adopt similar data collection and evaluation approaches.

Perhaps the most important component of sustaining state innovation is identifying programs and activities that can be scaled back or eliminated, because the market has developed to the point where fewer state incentives are needed or because prospects for success are limited. By reducing funding and support for some programs, states can free up resources for new cutting-edge initiatives.

As the federal government looks to the states to implement clean energy policies and regulations such as the Environmental Protection Agency’s forthcoming Clean Power Plan, it will remain important for states to continue their role as laboratories of experimentation and innovation. States must go beyond defending existing programs and embrace the challenge of creating new policy approaches. The next 15 years can be as groundbreaking for clean energy as the past 15 — as long as the states continue to develop emerging clean energy technologies while refining existing successful programs.

Warren Leon was appointed executive director of CESA in June 2013. He is an Adjunct Professor at the Brandeis University International Business School and head of the school’s sustainability specialization. He co-authored the influential book The Consumer’s Guide to Effective Environmental Choices.